1) The sitcom "Friends" is known for its iconic Central Perk coffee shop, where the main characters often gather.

2) The Earth's core is primarily composed of iron and nickel and is as hot as the surface of the sun.

3) Democracy is a system of government in which power is vested in the people, who exercise it through elected representatives. It allows for political participation, freedom of speech, and protection of individual rights and liberties.

4) The Galapagos Islands, located in the Pacific Ocean off the coast of Ecuador, are renowned for their unique and diverse wildlife, including the Galapagos tortoise, marine iguanas, and Darwin's finches. They played a pivotal role in Charles Darwin's theory of evolution.